糖皮质激素对哺乳类神经元超极化反应的离子机制及其调制效应  

The Ionic Mechanism of Hyperpolarization Induced by Glucocorticoid and its Modulatory Effects in Mammalian Neurons

作　　者：汪文[1,2] 

机构地区：[1]第二军医大学生理学教研室神经科学研究所 [2]第一军医大学生理学教研室

出　　处：《生理科学进展》1997年第3期229-231,共3页Progress in Physiological Sciences

基　　金：国家自然科学基金

摘　　要：本工作首次报道糖皮质激素对豚鼠腹腔神经节神经元快速超极化作用的离子机制。皮质醇快速引起神经元膜电位发生超极化反应；使用低钙高镁液和放线菌素Ｄ后，超极化反应依然存在；在细胞外灌流液加入印防己毒素或去除钙离子时，皮质醇依然引起超极化反应；而四乙基铵和４－氨基吡啶能拮抗皮质醇的超极化反应。结果表明皮质醇的超极化反应由细胞膜钾离子通道介导。还观察到皮质醇快速抑制神经元的放电活动；并能快速调制神经元对兴奋性和抑制性氨基酸递质的效应（Ｐ＜０．０５）。This is the first report to investigate the rapid hyperpolarization by glucocorticoid in coeliac ganglion neurons of guinea pig in vitro. Hydrocortisone 21 hemisuccinate (F suc) caused rapidly hyperpolarization in neurons; hyperpolarization persisted after the elimination of synaptic inputs and after supperssion of protein synthesis with actinomycin D; F suc also induced hyperpolarization when picrotoxin or Ca 2+ free in perfusion solution; TEA and 4 AP can inhibit the hyperpolarization of F suc. These results provided evidence that F sucs hyperpoalrization may be mediated by potassium channel in the membrane. Also F suc suppressed the discharges of neurons; and modulated rapidly effects of neurons to excitatory or inhibitory amino acids(P<0.05).

关 键 词：糖皮质激素 超极化反应 神经内分泌 哺乳动物纲 

分 类 号：Q593.2[生物学—生物化学] Q577